Solubility and absorption rate of carbon dioxide into non-respiring foods. Part 3: Cooked meat products

The solubility and diffusion of carbon dioxide into cooked meat products (cooked ham and meat sausage with different pH-levels) was determined at different starting pressures and gas to product volume ratios by monitoring pressure changes over time in a closed chamber at constant temperatures (0, 4, and 8 °C). Good correlation of the CO₂ solubility between the packaging parameters (gas to product volume ratio and initial partial pressure) and the meat products water content was found. The solubility of CO₂ followed Henry’s law and the initial partial pressure of CO₂ influenced the solubility mostly. Only small variations in the diffusion constants and absorption rates were found within the experimental design. A pH difference of 0.5 in the two meat sausage types did not influence either solubility or diffusion significantly.     

Die verbrennungstechnische Entsorgung eines Chemiebetriebes

Incineration of waste from a chemical facility. Waste from chemical plants includes solids, liquids, gases – all of which require disposal. Solid and liquid wastes can be readily incinerated or deposited in a central plant. Gas purification is the final step of the process, performed at a limited distance from the production plant. If several substances having different properties are involved then thermal waste air purification is appropriate. This paper considers the design concepts of such a thermal waste air purification unit.     

Antimicrobial enzymes: Applications and future potential in the food industry

Antimicrobial enzymes are ubiquitous in nature, playing a significant role in the defense mechanisms of living organisms against infection by bacteria and fungi. Hydrolytic antimicrobial enzymes function by degrading key structural components of the cell walls of bacteria and/or fungi, whereas antimicrobial oxidoreductases exert their effects by the generation in situ of reactive molecules. The potential of these enzymes in food preservation is still far from realized at present.     

Vitamin D₂ impairs utilization of vitamin D₃ in high-yielding dairy cows in a cross-over supplementation regimen

Vitamin D exists in 2 forms that are important regarding vitamin D status and supply in cattle: vitamin D₂ (D₂) and vitamin D₃ (D₃). To become physiologically active, both D₂ and D₃ must undergo 25-hydroxylation in the liver. The resulting 25-hydroxyvitamin D₂ [25(OH)D₂] and 25-hydroxyvitamin D₃ [25(OH)D₃] are measured as indicators of the physiological vitamin D status of cattle. The study used 14 Danish Holstein cows housed without access to sunlight. The cows were orally administered 250 mg (1.0 × 10⁷ IU) of D₂ and D₃ in a cross-over design with 2 treatment groups and 2 study periods, rendering 4 treatments when carryover effects were taken into account: D₂ given first, D₂ given last after D₃, D₃ given first, and D₃ given last after D₂. Two weeks elapsed between the treatment in the first study period and the treatment in the second study period. Blood samples were collected 0, 3, 6, 14, 17, 20, 23, 26, 40, 48, 70, 94, 166, and 214 h after providing the oral bolus of vitamin to the cows. Comparisons between plasma levels of the metabolites D₂, D₃, 25(OH)D₂, and 25(OH)D₃ over time were made by comparing areas under the plasma concentration curves. Oral administration of D₃ increased plasma D₃ (182.6 ± 17.1 ng/mL; mean ± SEM) and 25(OH)D₃ (103.5 ± 10.0 ng/mL) more efficiently than oral administration of D₂ increased plasma D₂ (49.1 ± 32.6 ng/mL) and 25(OH)D₂ (27.9 ± 2.1 ng/mL). The D₃ given after an oral dose of D₂ was less efficient for increasing plasma concentrations of 25(OH)D₃ (61.2 ± 12.0 ng/mL) compared with D₃ given without previous D₂ administration (103.5 ± 10.0 ng/mL), whereas the plasma concentrations of D₃ itself were the same when given first (182.6 ± 17.1 ng/mL) as when given after D₂ (200.0 ± 123.9 ng/mL). The same occurred for plasma concentrations of D₂ metabolites both if D₂ was given first (49.1 ± 32.6 ng/mL) and after D₃ (54.7 ± 7.7 ng/mL). In conclusion, D₃ given after D₂ is less efficient at increasing the plasma status of 25(OH)D₃ than D₃ given without previous D₂ administration.     

Effects of dietary α-tocopheryl acetate supplementation on α-tocopherol deposition in porcine m. psoas major and m. longissimus dorsi and on drip loss, colour stability and oxidative stability of pork meat

The effect of feeding supra-nutritional levels of α-tocopheryl acetate on its deposition in two porcine muscles of different metabolic rates (m. longissimus dorsi and m. psoas major) and the effect on meat quality (lipid oxidation, colour stability and drip loss) was studied. Pigs were fed a standard diet supplemented with three levels: 100, 200 and 700 mg/kg of α-tocopheryl acetate from the time of weaning to slaughter at 90kg live weight. Muscle α-tocopherol levels were linearly related to the logarithm of dietary α-tocopheryl acetate supplementation and the linear relationship was estimated for the two muscles. The levels of α-tocopherol in the two muscles differed by a parallel displacement with consistently higher α-tocopherol levels in m. psoas major compared to m. longissimus dorsi. Dietary α-tocopheryl acetate supplementation significantly reduced lipid oxidation as measured by thiobarbituric acid reactive substances (TBARS) in both raw and cooked meat during storage at 4 °C for 6 days. Drip loss and colour stability of raw muscles were not affected by dietary α-tocopheryl acetate levels, 100mg α-tocopheryl acetate/ kg feed resulted in sufficient α-tocopherol levels in muscles to ensure minimum drip loss and optimum colour stability.     

Olfactory and quantitative analysis of volatiles in elderberry (Sambucus nigra L) juice processed from seven cultivars

Aroma compounds emitted from elderberry juices processed from seven cultivars were collected by the dynamic headspace technique and analysed by GC–FID and GC–MS. Forty aroma compounds were identified and quantified, including nine compounds which had not previously been detected in elderberry juice. Significant differences were found among cultivars in the concentration levels of 30 compounds. The sensory characteristics of the individual aroma compounds in elderberry juice were determined by a GC‐sniffing technique, and the compounds were grouped according to their odour. The characteristic elderberry odour is due to dihydroedulan and β‐damascenone, of which the former occurs in relatively high concentrations in the headspace of elderberry juice. The fruity group consisted of aliphatic alcohols and aldehydes and aromatic esters, of which 1‐pentanal, 2‐methyl‐1‐propanol, 2‐ and 3‐methyl‐1‐butanol, 1‐octanal, 1‐octanol and methyl and ethyl benzoate contributed with fruity notes. In the flowery group, 1‐nonanal, nerol oxide and (Z)‐ and (E)‐rose oxide contributed with characteristic elder flower odour, whereas other flowery notes were associated with hotrienol, linalool and α‐terpineol. Fresh and grassy odours were correlated with 1‐hexanal, (E)‐2‐hexen‐1‐al, (Z)‐3‐hexen‐1‐ol, (E)‐2‐hexen‐1‐ol and (E)‐2‐octen‐1‐al of the grassy group, whereas 1‐octen‐3‐ol and 1‐octen‐3‐one of the agrestic group contributed significantly with the characteristic aroma of mushrooms. © 2000 Society of Chemical Industry     

Safety tests and antinutrient analyses of noni (Morinda citrifolia L.) leaf

BACKGROUND: Noni (Morinda citrifolia L.) leaves have a documented history of food use. However, previous safety and antinutrient studies are absent. The current investigation was conducted to assess the utility of noni leaves as food. RESULTS: No evidence of toxicity or differences in weight gain were observed in acute, subacute, and subchronic oral toxicity tests of ethanol–water (1:1 v/v) and hot‐water extracts of noni leaves in mice at doses of 2000, 200, and 20 mg kg^?1 body weight, respectively. Acute systemic anaphylaxis tests of the ethanol–water (4:1 v/v) and hot‐water extracts were negative. Further, leaf proteins were readily digested in simulated gastric fluid. Tannic acid concentrations in frozen and dried leaf were 1.6 and 25.8 g kg^?1, respectively. Phytic acid was not detected in the raw leaf (<1 g kg^?1). The average oxalic acid content was 1 g kg^?1 and was fairly uniform among 22 leaf samples from 11 islands throughout French Polynesia. Similarly, campesterol, stigmasterol, and β‐sitosterol content did not vary widely, suggesting low inter‐island content variability. CONCLUSIONS: The apparent lack of toxicity of the leaves and the hardiness of the plant make it ideal for further agricultural development, especially where sustained growth of other food crops is difficult. Copyright © 2007 Society of Chemical Industry     

Changes in liquid‐holding capacity,water distribution and microstructure during chill storage of smoked salmon

BACKGROUND: During recent years, increases in liquid loss and soft texture in cold smoked salmon have been reported, possibly due to increased lipid content and a change in muscle structure. These problems can lead to downgrading of the product. This study aimed to investigate the influence of raw material composition and chill storage on quality parameters of cold smoked salmon. RESULTS: Initial smoked fish had a higher liquid‐holding capacity (LHC) than samples stored for 20 days. Large fish lost more liquid than small fish. The difference in LHC was consistent with a change in water distribution, which could indicate denaturation of muscle protein. Studies of the microstructure showed the influence of both processing and chill storage. An indication of lipid released from the cells was seen after 20 days of chill storage, which could be related to the reduced LHC at that time. CONCLUSION: Both raw material composition and chill storage affected the quality parameters of smoked salmon. This study has improved knowledge about the relationships between muscle structure, liquid‐holding properties and water distribution in smoked salmon. Copyright © 2007 Society of Chemical Industry     

Glycogen content, buffering capacity and resting pH in live muscles of pigs of different halothane genotypes (a pilot project)

The development of PSE (pale, soft and exudative) meat is characterized by a rapid decrease in pH post-mortem and/or a low ultimate pH. We investigated some physiological properties of the live muscle (the glycogen content, the non-bicarbonate buffering capacity and 'resting pH'), which could influence both the decrease in pH and the ultimate pH. Measurements were performed on three halothane genotypes, hal(N)hal(N), hal(N)hal(n) and hal(n)hal(n), with their known predispositions for PSE meat. It was demonstrated that the glycogen content in both the groups of double recessive and heterozygous individuals was higher than the levels in the group of homozygous dominant pigs. No difference was found in non-bicarbonate buffering capacity between the groups. The groups with the highest glycogen levels also had the lowest 'resting pH' values. The results indicate that measurement of glycogen content in vivo may be superior to the halothane test in detecting PSE-prone individuals. The lower pH values of carriers of the hal(n) gene further indicate that the characteristic rapid decrease after slaughter may not be as fast as generally accepted, as even very low pH values can be observed in the muscles of live pigs.